Study Of Tiny Worms On Micro-Sized Chips Sheds Light On How Memories Are Formed In The Brain

“Nature has evolved a very efficient sensing system for the worms. The worms are very good at finding mates, finding food, avoiding predators and finding a good home. We’re hoping we can learn a lot from this highly evolved sensing system,” Lu said.

The key is deciphering how the very small worms (about 50 microns in diameter, much smaller than the diameter of a human hair, and with only 302 neurons altogether) integrate their keen sensory information about their environment into their brain. A certain stimulus, such as the presence of undesirable bacterial food, triggers changes in sensory neurons that stimulate other neurons to give rise to an avoidance behavior, and can also create a memory imprint in the worm’s brain.

In order to figure out which neurons are activated for a particular behavior, Lu and her team use a laser beam to operate on worm neurons and then study the behavior after the lesion forms. A genetic technique is used to make certain neurons produce jellyfish’s green fluorescent protein, and the laser beam then targets the green neurons.

Since the worms and their neurons are so small, appropriate micro-sized devices have to be created to study them. By carefully controlling the types of stimuli the microscopic worms are exposed to via an intricate micro chip with stimulus delivery systems, Lu and her team can decipher what new sensory information is triggering which neurons that then produce proper behavior and form worm memory as a result.